It has previously been well known to employ counter pressure bottle filling machines for purposes of filling bottles or other containers with liquids such as beverages and the like. The structure of such filling machines, including the multiple filling heads typically employed therewith, are well known and documented such as in U.S. Pat. Nos. 3,757,835 and 4,688,608, assigned to the assignee of the instant application. The invention herein relates to bottle filling machines of the nature known from these prior art references, differing primarily in the construction and operation of the choke valve assembly.
It is well known that bottle filling machines typically include a reservoir of beverage or liquid having a pressure head maintained thereabove. The bottle filling machine typically has a plurality of identical bottle filling heads circumferentially spaced about the reservoir. Each bottle filling head has a resilient seal receiving and sealing the mouth of a bottle. A counter pressure tube extends into the bottle at one end thereof, and into the pressure head at the other. The tube has openings or orifices at each of the ends, the same being selectively sealed during the operation of the bottle filling machine.
Each of the bottle filling heads employs several valve systems controlling physical movement and/or opening and closing of the passage of the counter pressure tube. As will be appreciated from reference to prior U.S. Pat. No. 3,757,835, when a bottle is received by the resilient seal, a valve at the top of the counter pressure tube allows the pressure head above the reservoir to communicate with the interior of the bottle. The resulting pressure in the bottle opens a liquid valve assembly fixed to the bottom of the counter pressure tube. This liquid valve consists of a disc fixed to the counter pressure tube and having a tapered edge adapted to reciprocatingly engage with and separate from a fixed valve seat maintained adjacent the sealing member.
A choke valve is also maintained about the counter pressure tube and is opened by the pressure of the beverage and the flow of the beverage thereacross upon opening of the liquid valve. When the beverage in the bottle reaches the level of an aperture or apertures in the end of the counter pressure tube, the flow of the beverage stops, for backflow of the counter pressure gas through the counter pressure tube is prevented.
Immediately upon cessation of beverage flow, the choke valve closes by spring actuation. An inner tapered surface of the choke valve sealingly engages a portion of the tapered edge of the disc of the liquid valve. The closure is attained by overlapping engagement of the parallel tapers of the choke valve and the disc of the liquid valve. This closure immediately prevents any further flow of beverage into the bottle for release of gas from the bottle. Immediately thereafter, conventional control of a lever arm moves the counter pressure tube downwardly, causing the disc of the fluid valve to close against its seat, allowing the bottle to be removed, capped, and cased.
While the prior art discussed above has been generally successful in filling bottles and other containers, certain problems are inherent with its structure and operation. Particular problems have been observed with respect to the choke valve used in such filling heads. The seal of the choke valve has been found to be given to sticking due to the overlapping mating engagement of the tapered surfaces of the choke valve and the liquid valve disc. Such sticking results in delays in operating time, reducing the efficiency of operation of the filling machine. Further, the prior choke valve has been given to the generation of turbulence during flow and upon the closure thereof. This turbulence is the result of path restrictions between the valve members when the valve is opened, as well as the abrupt positive action of closure of the valve upon actuation. Such turbulence generates foam in carbonated beverages, a most undesirable occurrence.